A variety of display devices ranging from large display devices such as television receivers to small display devices such as cellular phones are put on the market. High-value-added products are needed and are being developed. In recent years, display devices that can display stereoscopic images have been developed in order to display more realistic images.
Physiological factors in recognition of objects as stereoscopic objects by humans are binocular parallax, convergence, focus slide, motion parallax, object size, spatial layout, contrast, shading, and the like.
Display devices employ methods utilizing binocular parallax as methods for displaying stereoscopic images in many cases. As a method utilizing binocular parallax, for example, there is a method of using special glasses for separating an image perceived by a left eye and an image perceived by a right eye. Further, as a method without using special glasses, there is a method of adding a mechanism (e.g., a parallax barrier, a lenticular lens, or a microlens array) for separating an image perceived by a left eye and an image perceived by a right eye to a display portion and displaying an image that can be perceived as a stereoscopic image by the naked eye (e.g., Patent Document 1).
[Reference]
Patent Document 1: Japanese Published Patent Application No. 2005-258013.